Se você não tem medo de sujar as mãos, a melhor maneira de fazer isso é:
apt-cache show nome do pacote
Ele mostrará todas as versões diferentes do pacote que você pode instalar, de acordo com sua definição de sources.list. Você obterá algo assim (é assim que parece para mim):
root@shiny-desktop:/home/shiny# apt-cache show libpulse-browse0
Package: libpulse-browse0
Status: install ok installed
Priority: optional
Section: sound
Installed-Size: 100
Maintainer: Ubuntu Core Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Architecture: i386
Source: pulseaudio
Version: 1:0.9.15-4ubuntu2~ppa1
Depends: libavahi-client3 (>= 0.6.16), libavahi-common3 (>= 0.6.16), libc6 (>= 2.4), libcap1, libdbus-1-3 (>= 1.0.2), libgdbm3, libice6 (>= 1:1.0.0), libpulse0 (= 1:0.9.15-4ubuntu2~ppa1), libsm6, libwrap0 (>= 7.6-4~), libx11-6, libxtst6
Description: PulseAudio client libraries (zeroconf support)
PulseAudio, previously known as Polypaudio, is a sound server for POSIX and
WIN32 systems. It is a drop in replacement for the ESD sound server with
much better latency, mixing/re-sampling quality and overall architecture.
.
Client libraries used by applications that access a PulseAudio sound server
via PulseAudio's native interface.
.
This package adds support for zeroconf (aka. Avahi, mdns) discovery of
PulseAudio sinks and sources by client applications.
Homepage: http://www.pulseaudio.org
Original-Maintainer: Pulseaudio maintenance team <pkg-pulseaudio-devel@lists.alioth.debian.org>
Package: libpulse-browse0
Priority: optional
Section: sound
Installed-Size: 144
Maintainer: Ubuntu Core Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Pulseaudio maintenance team <pkg-pulseaudio-devel@lists.alioth.debian.org>
Architecture: i386
Source: pulseaudio
Version: 1:0.9.14-0ubuntu20.2
Depends: libavahi-client3 (>= 0.6.16), libavahi-common3 (>= 0.6.16), libc6 (>= 2.4), libcap2 (>= 2.11), libgdbm3, libice6 (>= 1:1.0.0), libpulse0 (>= 0.9.14), libsm6, libx11-6
Filename: pool/main/p/pulseaudio/libpulse-browse0_0.9.14-0ubuntu20.2_i386.deb
Size: 31522
MD5sum: d7bf325c04432507420551d7c4e04737
SHA1: 537037b6cdcf2e36ab91fff73a543b2bc9a9d2f6
SHA256: 25c9a83f669f3f14b0fdd59141fc048e3053ccdcae5817f338260342ae1164d0
Description: PulseAudio client libraries (zeroconf support)
PulseAudio, previously known as Polypaudio, is a sound server for POSIX and
WIN32 systems. It is a drop in replacement for the ESD sound server with
much better latency, mixing/re-sampling quality and overall architecture.
.
Client libraries used by applications that access a PulseAudio sound server
via PulseAudio's native interface.
.
This package adds support for zeroconf (aka. Avahi, mdns) discovery of
PulseAudio sinks and sources by client applications.
Homepage: http://www.pulseaudio.org
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
Task: ubuntu-desktop, kubuntu-dvd-live, edubuntu-desktop, xubuntu-live, mobile-mid, mobile-netbook-remix
Package: libpulse-browse0
Priority: optional
Section: sound
Installed-Size: 144
Maintainer: Ubuntu Core Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Pulseaudio maintenance team <pkg-pulseaudio-devel@lists.alioth.debian.org>
Architecture: i386
Source: pulseaudio
Version: 1:0.9.14-0ubuntu20
Depends: libavahi-client3 (>= 0.6.16), libavahi-common3 (>= 0.6.16), libc6 (>= 2.4), libcap2 (>= 2.11), libgdbm3, libice6 (>= 1:1.0.0), libpulse0 (>= 0.9.14), libsm6, libx11-6
Filename: pool/main/p/pulseaudio/libpulse-browse0_0.9.14-0ubuntu20_i386.deb
Size: 31516
MD5sum: 63d4937b22f83cff5cc5be101caa3f27
SHA1: bb436fa7bc14eaad31a9f3778f1a887d96e2521d
SHA256: 1f3a5e7a4376c0ee406f30a1c5ec03dc5f484dc059ceb61462516bb728c6c1c5
Description: PulseAudio client libraries (zeroconf support)
PulseAudio, previously known as Polypaudio, is a sound server for POSIX and
WIN32 systems. It is a drop in replacement for the ESD sound server with
much better latency, mixing/re-sampling quality and overall architecture.
.
Client libraries used by applications that access a PulseAudio sound server
via PulseAudio's native interface.
.
This package adds support for zeroconf (aka. Avahi, mdns) discovery of
PulseAudio sinks and sources by client applications.
Homepage: http://www.pulseaudio.org
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
Task: ubuntu-desktop, kubuntu-dvd-live, edubuntu-desktop, xubuntu-live, mobile-mid, mobile-netbook-remix
Basta verificar a versão diferente disponível para você e depois:
apt-get install packagname=version
Novamente, como exemplo para a saída acima:
apt-get install ibpulse-browse0=1:0.9.14-0ubuntu20
Como você pode ver, o meu pulseaudio é de um ppa na barra de ativação; portanto, se eu quisesse fazer o downgrade / reverter para o original fornecido pela jaunty, faria o mencionado acima com todos os pacotes do pulseaudio que instalei.
apt-cache policy <packagename>
, o que mostrará apenas as versões disponíveis e suas fontes, para que você obtenha exatamente as informações necessárias em vez de todo o material extra queapt-cache show
fornece.